Vertex Mh-360s Remote Speaker Microphone Vx-180 Vx-210 Vx-410 Vx-424 Vx-231 Vx-351 Vx-354 Vx-451 Vx-454 Vx-459 Evx-531 Evx-534 Evx-539 3.5mm audio jack (for listen only earpiece)